Controlling vegetation with aryloxyethyl esters of diallylthiocarbamic acids



United States Patent CONTROLLING VEGETATION WITH ARYLOXY- ETHYSL ESTERS 0F DIALLYLTHIOCARBAMIC ACID Anton G. Weiss, Nitro, W. Va., and Philip C. Hamm,

Webster Groves, Mo., assignors to Monsanto Company, a corporation of Delaware No Drawing. Original application Oct. 7, 1959, Ser. No. 844,872. Divided and this application Sept. 26, 1962, Ser. No. 253,235

5 Claims. (Cl. 71--2.6)

The present invention relates to new compounds and more particularly to aryloxyethyl esters of diallylthiocarbamic acids.

The present application is a division of copending ap plication Serial No. 844,872, filed October 7, 1959.

The compounds of the present invention may be represented by the general formula where R represents phenyl or halogen substituted phenyl, Y represents'oxygen or sulfur, X and X represent oxygen or sulfur at least one of which is sulfur and R and R" represent allyl or chloroallyl. Typical examples of the preferred compounds comprise 2-(phenylthio)ethyl, 2- (phenoxy)ethyl, 2-(p-chlorophenylthio)ethyl, 2-(p-chlorophenoxy)ethyl, Z-(p-bromophenylthio)ethyl, 2-(p-bromo-phenoxy)ethyl, 2-(2,4-dichlorophenylthio)ethyl, 2- (2,4-dibromophenylthio)ethyl, 2-(2,4-dichlorophenoxy) ethyl, 2-(2,4-clibromophenoxy)ethyl, 2-(2,4,5-trichlorophenylthio)ethyl and 2 (2,4,5trichlorophenoxy)ethyl esters of diallyldithiocarbamic acid, diallylthiolcarbamic acid and diallylthionoearbamic acid. I

Although other methods of preparation are suitable, such thiocarbamates-may. be conveniently obtained by convertingv diallylamine to a thiocarbamic acid and conand the mixture stirred for 5 hours at -70" C. After coolingto room temperature, 250 ml. of water were added to the product and the water solution extracted with 250 ml. of ether. The organic layer which separated waswashed with 300 ml. of water and dried over sodium sulfate. The solvent was removed by stripping at90-l00 C.(l4-mm. pressure). The 2-(p-chlorophenoxy)ethyl diallyldithiocarbzam-ate, obtained in theory yield, was an amber oil analyzing 4.6% nitrogen, 10.9% chlorine and 19.8 sulfur as compared to 4.3% nitrogen, 10.8% chlorine and 19.6% sulfur calculated for The new compounds exert significant biological activity. In'general they are efficient herbicides which combine grass and broadleaf activity. They are particularly effective in preemergent application. Amounts within the range of 1 to 60 pounds per acre are adequate for most purposes. The toxicants may be applied in the form of a spray containing the active ingredient in a concentration within the range of 0.055.0%. While the active components are insoluble in water they are soluble in common organic solvents. They may be dispersed directly in water or dissolved first in an organic solvent and then dispersed. As dispersing and wetting agents there may be As an illustration" 3,166,401 Patented Jan. 19, 1965 "ice.

employed soft or hard sodium or potassium soaps, alkylated aromatic sodium sulfonates such as sodium dodecylbenzenesulfonate, or an amine salt thereof, alkali metal salts of sulfated fatty alcohols, ethylene oxide condensation products of alkyl phenols, tall oil, higher alcohols or higher mercaptans. The solid formulations or dusts may contain in addition to the active ingredient, diluents or extenders, preferably those which render the formulations permanently dry and free flowing. Effective solid diluents are clay, talc, pyrophyllite, silica and fullers earth.

As illustrative of the herbicidal activity the ester was emulsified in water and the emulsion applied as a spray. In this manner the active ingredient was applied to the soil of seeded plots before any 'plants emerged. About fourteen days after application of the .toxicants results were observed and recorded. The number of seeds emerging was converted to weighted herbicidal ratings based on average percent germination of any particular seed lot times an injury factor. This evens irregularities of ratings on seeds which may vary in percent germination. The injury factor takes into consideration any plants not expected to survive. Thus, phytotoxici'ty ratings are based on the number of plants which emerge and will survive as observed two weeks after planting. Herbicidal ratings were assigned by means of the following COHVGISIOH scale:

Percent emergence: Phytotoxlclty ratlng 0-25 3 or severe.

26-50 2 or moderate.

51-75 1 or slight. 76-100 0 or none.

T able. 1

. Active Ingredient Lbs/Acre Results Observed 2-(Phenoxy) ethyl 25 Severe phytotoxieity to a mixdiallylthiolcarbamate. tore-of grasses, wild oat, rye grass, sugar beet, -foxtail, crab grass, pigweed and sorghum; moderate phytotoxicity to brome grass. Z-(Phenylthio) ethyl -25 Severe phytotoxicity to sugar diallylthiolcarbarnate. beet andcrab grass;.moderate phytotoxiclty to wild oats. 2-(2,4,5-Tricl1loro- Q 5 Severe phytotoxicity to morning phenoxy)-ethyl A e glory, radlsh and pigweed; diallylthiolcarbamate. moderate phytotoxieity to a mixture of broadleaved plants,

. sugar beet and crab grass. 2-(2,4-Dichlor0phenoxy) 5 Severe phytotoxicity to .wild ethyl diallyloats, rye grass, radish. sugar thiolcarbamate. beet, crab grass and wild buckwheat; moderate phytotoxicity to a mixture of grasses,

a mixture of broadleaved plants, brome grass and pigweed.

Z-(p-Chlorophenoxy). 25 Severe phytotoxicity to a mixethyl diallylture' of grasses, wild oats, thiolcarbamate. brome grass, rye grass, loxtail,

crab grass and sorghum;

moderate phytotoxicity to red- 4 a 4 ish and sugar beet. 2-(p-Bromophen0xy) 25 Severe phytotoxicity to a mixture ethyl diallylof grasses, a mixture of broadthiolcarbamate. leaved plants, morning glory, wild oat, radish, sugar beet.

crab grass, pigweed and soybean moderate phytotoxicity to brome grass, rye grass, toxtall, wild buckwheat and tomato.

2-(2,4,6-Trichlor0- 25 Severe phytotoxicityto a mixture phen0xy)-ethyl of broadleaved plants, radish, diallylthiolea-rbamate. sugar beet, crab grass, pigweed, wild buckwheat and tomato; moderate phytotoxicity to morning glory, rye grass and soybean.

2-(2,4Dichlorophenoxy) ethyl 2-(2,4,5-Trichlorophenoxy)- V 2-'(Plienoxy) ethyl diallyldi- Useful properties as contact herbicides are illustrated by applying the compounds in spray form to 21 day old specimens of a mixture of grasses and a mixture of broadleaved plants and observing the phytotoxicity. Typical results are recorded in Table II. The mixture of grasses is indicated as Grass and the mixture of broadleaved plants is indicated as Broadleaf in the table. A spray containing 0.5% of the active ingredient shown was applied:

Table III further illustrates the pre-emergent herbicidal activity of typical compounds. The active ingredient was applied at a dosage of 25 pounds per acre to the soil of seeded plots before the grass or other plants emerged:

Table 111 Active Ingredient Results Observed Z-(p-Chlorophenoxy) ethyl Severe phytotoxicity to radish and crab diallyl-dithiocarbamate.

grass; moderate phytotoxicity to morning glory, sugar beet, foxtail, Wild buckwheat, tomato and sorg um. 7 Severe phytotoxicity to morning glory, radish, sugar beet, foxtail, crab grass, pigweed, soybean and sorghum; moderate phytotoxicity to brome grass and tomato. Severe phytotoxicity to morning glory,

diallyldithiocarbamate.

ethyl diallyldithiocarbamate.

icity to wild cat, brome grass, ioxtail, crab grass and Wild buckwh eat.- Severe phytotoxicity to wild oat and thiocarbamate. crab grass; moderate phytotoxicity andtomato.

typical compounds at'5 pounds peracres i I fTable IV Table IV illustrates pre emergent herbicidal activity of v I Active Ingredient V V .Results oibserved 2-(2,4,5-Trichlorophenoxy)- 2-'(-2,4-Dich1orophenoxy)ethyl ethyldiallylt-hionooarbamate. f y

2'(2,4-Dichlorophenoxy)ethyl diallylthionocarbamate.

bistZ-ehloroallyl) dlthio} carbamate tomato.

radish, sugar beet, pigweed, tomato and sorghum; moderate phytotox- I to brome grass, sugar beet, soybean Severe phytotoxicity to morning glory,

glory, radish, wild buckwheat and It is intended to cover all changes and modifications of the examples of the invention herein chosen for purposes of disclosure which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

1. The method of controlling vegetation which comprises applying thereto a phytotoxic concentration of a phytotoxic thiocarbamate of the structure where R represents a member of the group consisting of phenyl and halogen substituted phenyl containing at least one, but not more than three, halogen atoms selected from the group consisting of chlorine and bromine, Y, X and X represent amember of the group consisting of oxygen and sulfur at least one of X and X being sulfur and R and R represent radicals selected from the group consisting of allyl monochloro substituted allyl.

2. The method of controlling vegetation which comprises applying thereto a phytotoxic concentration of a phytotoxic thiocarbamate of the structure 28 O CHzCH-OH ROCgHrS -N 30 where R represents a middle halogen substituted phenyl radical containing at least one but less than four middle halogen atoms.

3. The method of controlling vegetation which comprises applying thereto a phytotoxic concentration of 2- 5 (phenoxy)ethyl diallylthiolcarbamate.

. 4. The method of controlling vegetation which comprises applying thereto a phytotoxic concentration of 2- (phenoxy)ethyl diallyldithiocarbamate.

, 5. The method of controlling vegetation which comprises applying thereto a phytotoxic concentration of a phytotoxic thiocarbamate of the structure 7 g s CHzCH-CHg ROC HrOti-N l CH3CH-CH2 radicalcontaining at least one but less than four middle 7 halogen atoms. References Cited in the file of this patient UNITED STATES PATENTS 2,941,879 Goodhue June 21, 1960 FOREIGN PATENTS J 7 V Australia"; I AE Feb. 6 1958 OTHER REFERENCES. 5 Nature, v01 176, pages 308 to :31 0, August 13, 1955.

r where R represents a middle halogen substituted phenyl Harman et al., July 11, 1961 Tilles et a1. *Sept. 25, 1962 

1. THE METHOD OF CONTROLLING VEGETATION WHICH COMPRISES APPLYING THERETO A PHYTOXIC CONCENTRATION OF A PHYTOTOXIC THIOCARBAMATE OF THE STRUCTURE 